Researchers at the University of British Columbia analysed the employment records of a major retailer to find out why the firm had such high staff turnover. The team examined data on around 1 million workers, noting how and when they left their jobs. The researchers also looked at their work performance records so they could identify both high and low achievers . They found that when high-achievers leave, other high-achievers tend to follow. Layoffs have the strongest and fastest effect. When high achievers are laid off, both high and low achievers will follow them. As layoffs are seen as a sign that no one’s job is secure.